Asphalt packets, asphalt mixture systems and related methods

ABSTRACT

Asphalt packets and methods of making and using asphalt packets are provided. For example, an asphalt packet can be provided that include asphalt that comprises an inner volume and a polymer film outer coating that encapsulates the inner volume of the asphalt. The polymer film outer coating can be non-tacky at ambient temperatures to permit stacking of a plurality of asphalt packets under weight without causing the packets to agglomerate.

RELATED APPLICATION

The presently disclosed subject matter claims the benefit of U.S. patentapplication Ser. No. 16/255,415 filed Jan. 23, 2019, the disclosure ofwhich is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present subject matter relates to asphalt packets, asphalt mixturesystems, and related methods. In particular, the present subject matterrelates to asphalt packets that can be stored together at ambienttemperatures separate from any aggregate used in a hot mix asphaltwithout fear of adhesion to other packets and aggregation that causesthe asphalt packets to clump together.

BACKGROUND

Hot mix asphalt (hereinafter “HMA”) or stone matrix asphalt (hereinafter“SMA”) is commonly used in highway construction for paving both in newroad construction and in maintenance of existing roads which havesurface cracks or potholes. Similarly, HMA and SMA mixes are used inairfield construction for paving both new runways and in maintenance ofexisting runways. These HMA and SMA mixes are currently produced instationary plants utilizing liquid asphalt stored at temperature abovethe melting point typically above 250° F. to 300° F. This liquid asphaltis then pumped into a gradation of heated stone aggregated which has aspecific particle size distribution properly suited for the paving orrepair application. Different gradations are used for differentapplications, usually ranging in particle size from material passing 200mesh (0.003 inch) to 0.75- or 1-inch diameter. About 5% to 7% by weightasphalt is mixed with the aggregate to produce HMA or SMA. Plasticasphalt utilizing polymers as binders for the aggregate have also beenused.

The creation and use of HMA and SMA mixes can be challenging, since boththe HMA and SMA mixes and the asphalt used in the HMA and SMA mixesrequire the use of large amounts of energy to be maintained atrelatively high temperatures until used. For example, the transport ofsuch asphalt to be used as binder in the various asphaltic mixtureapplications can be problematic. Typically, asphalt is handled in bulkform as a hot liquid due to the fact that the material tends to sticktogether as individual particles even at room temperature when stored inthe same container. During processing in anticipation for use, theasphalt must be kept heated at over 275° F. in liquid form forsubsequent handling and mixing. For example, asphalt binder is handledas a hot liquid from its origination point, usually the refinery, withheated rail cars or trucks. The asphalt binder remains heated in itsliquefied state through shipment to and during use in the asphalt mixplant. Since such material must be maintained at elevated temperaturesfor transfer to storage tanks and any transfer from one container toanother until ultimate use, significant amounts of energy in the form ofheat must be expended in order to maintain the asphalt in its liquefiedstate. It is estimated that, in the United States alone, over 20 billionpounds of liquid asphalt is used each year for paving, all of which mustbe kept continuously heated prior to use. Depending on any additives orother materials added to the asphalt, maintaining the asphalt atelevated temperatures for prolonged periods can adversely affect theproperties of the asphalt.

Similarly, problems arise in the transport of the HMA and SMA mixes. Topave roads which may be 30 or 50 miles or more from the mix plant, verycareful and difficult coordination is required between the production ofthe hot HMA and SMA mixes at the plant, the use of large trucks withconsequent traffic control, the need to maintain the HMA and SMA mixesat a controlled temperature to the jobsite, and the coordination of thepaving crew and equipment for proper installation of the HMA and SMAmixes for paving and patching roads, bridge decks, parking lots, airportrunways, and other paving jobs. The maintenance of proper temperature ofthe HMA and SMA mixes is difficult to control due to the long distancesthe mixes are hauled. This failure of maintain the proper temperatureoften presents problems.

Situations which present particular difficulty using these fixed planttrucking systems are maintenance, patching, and off-season work. Forexample, roads, including high traffic roads, that are remote from amixing plant may be damaged creating situations involving security andsafety risks where quick local action is required. As another example,remote airfields may become damaged thus rendering them unusable. Oftenmaintenance or pothole patching may only require a few tons of HMA orSMA at a location remote from a mixing plant. To send a truck with threeto five tons of HMA from a mix plant may take several hours of expensivelabor and equipment and often excess material is dumped on vacant land,creating an environmental hazard to be resolved later. This conventionalsystem is expensive and inefficient for use for small amounts ofmaintenance, patching, and off-season work, especially in remote areas.

A typical drum plant used to produce asphalt today can include a directfire continuous plant where the aggregate is introduced into a rotatingdrum, heated and dried to about 300° F., and liquid asphalt at about300° F. is then introduced toward the end of the drum into the hotaggregate and mixed in the last section of the drum and then dischargedas hot mix in a continuous method at about 300° F. Such a drum methodcan provide a continuous supply of asphalt at high throughput rates of200 to over 500 tons per hour. The liquid asphalt, however, must be kepthot continuously from the refinery, stored hot, and handled hot. Suchasphalt drum mix plants have other drawbacks that exacerbate thisheating problem including the facts that such plants are expensive, taketime and expertise to start up, require trained personnel to operate,and are not easily moved Further, it is difficult to meter the asphaltin a liquid in an accurate ratio generally within 1% with the continuousflow of aggregate to maintain high quality hot mix. Such processesrequire expensive sophisticated control systems to monitor and maintainthe process.

One alternative to hot mix patching is an emulsified asphalt mix appliedat ambient temperature with solvents and water evaporation afterplacement. These “cold” mix systems are inferior in quality and must bereplaced often. Also, they can be very expensive.

Another alternative uses small, portable mix units, typically 5 to 15tons/hr, to heat recycled asphalt (hereinafter “RAP”) for patching.These units do not produce HMA or SMA of adequate quality to meetpavement grade specifications. Further, many state departments oftransportation allow for only so much RAP in any given mixture ofasphalts. These units normally use open flame to heat the mix which haspreviously been coated with binder. This open flame can degrade the RAPmix which already has the binder coating. In order to reheat the RAPmix, the aggregate which has already been coated with asphalt or polymerbinders requires a large amount of heat to get the aggregate to aworking temperature of 300° F. to 350° F. Such a temperature will burnor thermally degrade the asphalt or polymer coating creating asubstandard product which will not meet the standards or specificationsof most state departments of transportation or specifications for newhot mix. Also, large amounts of smoke and unhealthy gases are produced.

To help mitigate some the problems outlined above with drum plantasphalt production as well as localized on-site small patch asphaltproduction, pelletized asphalt has been developed: Asphalt pellets canbe manufactured by a two-step coating process which produces pelletsthat are over 90% virgin performance grade asphalt and the coating ismostly a fine clay which forms part of the asphalt mix design. Thesepellets can then be evenly mixed in a package with other aggregates toform a prepackaged asphalt mix. All materials of aggregate and asphaltare measured accurately during packaging to assure accurateformulations. These measures combined with good mixing in the fieldproduce asphalt which is as good as or better than the virgin asphalthot mix produced in commercial mix plants with the advantage of beingcapable of being stored at ambient temperatures when integrated with theaggregate and produced in minutes in remote locations upon demand.Storage and transport of the prepackaged asphalt mix is at roomtemperature and greatly reduces the cost of keeping the asphalt hot andreduces the degradation and separation of the asphalt from its additivesover time.

The pellets are mixed with the proper aggregate mix design gradation,usually composed of 3 or 4 different gradations of aggregate fromapproved quarries to form a mixture of virgin asphalt and aggregate withthe accurate proportions of materials for a specific mix design. Thisasphalt mix is placed in one ton supersacks, 5 gallon pails, or othercontainers and can be stored on site at ambient temperature in remotelocations for up to 5 years or longer. When needed for fast repairs,this asphalt mix is placed in a direct or indirect fire rotating heatedmixer and can produce high quality hot mix in 10 minutes or moredepending on the mixer. This type of asphalt mix is currently used forrepair in military airfields and other critical locations for bothasphalt and concrete pavements, some of which are in remote locationsthat are thousands of miles from hot mix plants.

The accurate mixture of asphalt pellets and aggregate in a containersuch as a supersack which is transportable and storable at a remotelocation makes high quality repair of asphalt surfaces possible byproducing hot mix on site anytime with relatively low capital cost andunskilled labor without a mix plant. However, pelletization and coatingthe asphalt in a fine powder coating is expensive. Therefore, the costof producing the pelletized asphalt mix is costly. It is currently beingused in small quantities for critical reapplications where material costis not a major issue.

Further, pelletized asphalt provides fast melting and mixing of theasphalt with the aggregate under heated conditions, but when storing theasphalt pellets without aggregate the asphalt pellets tend to deformand/or break the coating under gravity due to about 30% free volume andform a non-flowable mix by interlocking the pellets, especially duringwarm weather. The two-step pellet forming process forms a brittlecoating due to the addition of powder which can crack upon deformationthus exposing the tacky asphalt which can cause pellets to sticktogether. A solution to the interlocking problem is to place the pelletsin a gradation of aggregate in which they will be used thus filling thevoids between the pellets with aggregate and thus preventing pelletdeformation while keeping the mix free flowing. However, the pelletsgenerally cannot be stored together without the aggregate for any lengthof time without the deformation and aggregation of the asphaltoccurring. By requiring the pellets of asphalt and the aggregate to bestored together, the cost of storage and material handling associatedwith the prepackaged asphalt mix grows substantially due to the size andweight of the aggregate involved as the aggregate is about 95% of theweight of the total mix, while the asphalt is about 5% of the weight.

Thus, a need exists for a hot mix asphalt system that can solve suchdifficult problems and facilitate quick preparations of asphalt mixeswith materials that can be transported and stored at ambient temperatureand can be later mixed together to produce hot mix at locations near thepaving site.

SUMMARY

The present subject matter provides asphalt packets, asphalt mixturesystems, and related methods. In particular, asphalt packets areprovided that can be stored together at ambient temperatures separatefrom any aggregate used in a hot mix asphalt without fear of adhesion toother packets and aggregation that causes the asphalt packets to clumptogether. Methods related to the manufacture and use of the asphaltpackets disclosed herein are also provided.

Thus, it is an object of the presently disclosed subject matter toprovide asphalt packets, asphalt mixture systems that use the asphaltpackets, and methods related to the use and manufacture of the asphaltpackets. While one or more objects of the presently disclosed subjectmatter having been stated hereinabove, and which is achieved in whole orin part by the presently disclosed subject matter, other objects willbecome evident as the description proceeds when taken in connection withthe accompanying drawings as best described hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present subject matter includingthe best mode thereof to one of ordinary skill in the art is set forthmore particularly in the remainder of the specification, includingreference to the accompanying figures, in which:

FIG. 1A illustrates a perspective view of an embodiment of an asphaltpacket according to the present subject matter;

FIG. 1B illustrates a cross-sectional view of the embodiment of theasphalt packet according to FIG. 1A taken along the dashed line BB;

FIG. 2 illustrates a perspective view of another embodiment of anasphalt packet showing the elements of heat transfer that determine theeffectiveness of the asphalt packet according to the present subjectmatter;

FIG. 3A illustrates a perspective view of an embodiment of a polygonalshaped asphalt packet according to the present subject matter;

FIG. 3B illustrates a cross-sectional view of the embodiment of theasphalt packet according to FIG. 3A taken along the dashed line BB;

FIG. 4A illustrates a perspective view of an embodiment of a sphericalshaped asphalt packet according to the present subject matter;

FIG. 4B illustrates a cross-sectional view of the embodiment of theasphalt packet according to FIG. 4A taken along the dashed line BB;

FIG. 5A illustrates a perspective view of an embodiment of a cylindricalshaped asphalt packet according to the present subject matter;

FIG. 5B illustrates a cross-sectional view of the embodiment of theasphalt packet according to FIG. 5A taken along the dashed line BB;

FIG. 6A illustrates a perspective view of an embodiment of a square-barshaped asphalt packet according to the present subject matter;

FIG. 68B illustrates a cross-sectional view of the embodiment of theasphalt packet according to FIG. 6A taken along the dashed line BB;

FIG. 7A illustrates a perspective view of an embodiment of a rectangularshaped asphalt packet according to the present subject matter:

FIG. 7B illustrates a cross-sectional view of the embodiment of theasphalt packet according to FIG. 7A taken along the dashed line BB;

FIG. 8 illustrates a schematic cross-sectional view of an embodiment ofa process for forming asphalt packet according to the present subjectmatter;

FIG. 9A illustrates a schematic top plan view of another embodiment of aprocess for forming asphalt packet according to the present subjectmatter;

FIG. 9B illustrates a cross-sectional view of the embodiment of theprocess for forming asphalt packet according to FIG. 9A;

FIG. 9C illustrates a schematic cross-sectional view of a furtherembodiment of a process for forming asphalt packet according to thepresent subject matter; and

FIG. 10 illustrates a graph of asphalt packet melt times versussurface-to-volume ratio of the asphalt packets based on the measurementspresented in Table 5 below.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the present subject matter.

DETAILED DESCRIPTION

Reference now will be made to the embodiments of the present subjectmatter, one or more examples of which are set forth below. Each exampleis provided by way of an explanation of the present subject matter, notas a limitation. In fact, it will be apparent to those skilled in theart that various modifications and variations can be made in the presentsubject matter without departing from the scope or spirit of the presentsubject matter. For instance, features illustrated or described as oneembodiment can be used on another embodiment to yield still a furtherembodiment. Thus, it is intended that the present subject matter coversuch modifications and variations as come within the scope of theappended claims and their equivalents. It is to be understood by one ofordinary skill in the art that the present discussion is a descriptionof exemplary embodiments only, and is not intended as limiting thebroader aspects of the present subject matter, which broader aspects areembodied in exemplary constructions.

Although the terms first, second, right, left, front, back, etc. may beused herein to describe various features, elements, components, regions,layers and/or sections, these features, elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one feature, element, component, region,layer or section from another feature, element, component, region, layeror section. Thus, a first feature, element, component, region, layer orsection discussed below could be termed a second feature, element,component, region, layer or section without departing from the teachingsof the disclosure herein.

Similarly, when a layer or coating is being described in the presentdisclosure as “on” or “over” another layer or substrate, it is to beunderstood that the layers can either be directly contacting each otheror have another layer or feature between the layers, unless expresslystated to the contrary. Thus, these terms are simply describing therelative position of the layers to each other and do not necessarilymean “on top of” since the relative position above or below depends uponthe orientation of the device to the viewer.

Embodiments of the subject matter of the disclosure are described hereinwith reference to schematic illustrations of embodiments that may beidealized. As such, variations from the shapes and/or positions offeatures, elements or components within the illustrations as a resultof, for example but not limited to, user preferences, manufacturingtechniques and/or tolerances are expected. Shapes, sizes and/orpositions of features, elements or components illustrated in the figuresmay also be magnified, minimized, exaggerated, shifted or simplified tofacilitate explanation of the subject matter disclosed herein. Thus, thefeatures, elements or components illustrated in the figures areschematic in nature and their shapes and/or positions are not intendedto illustrate the precise configuration of the subject matter and arenot intended to limit the scope of the subject matter disclosed herein.

It is to be understood that the ranges and limits mentioned hereininclude all ranges located within the prescribed limits (i.e.,subranges). For instance, a range from about 100 to about 200 alsoincludes ranges from 110 to 150, 170 to 190, 153 to 162, and 145.3 to149.6. Further, a limit of up to about 7 also includes a limit of up toabout 5, up to 3, and up to about 4.5, as well as ranges within thelimit, such as from about 1 to about 5, and from about 3.2 to about 6.5as examples.

As used herein, the term “polymer” generally includes, but is notlimited to, homopolymers; copolymers, such as, for example, block,graft, random and alternating copolymers; and terpolymers; and blendsand modifications thereof. Furthermore, unless otherwise specificallylimited, the term “polymer” shall include all possible geometricalconfigurations of the material. These configurations include, but arenot limited to isotactic, syndiotactic, and random symmetries.

The term “thermoplastic” is used herein to mean any material formed froma polymer which softens and flows when heated; such a polymer may beheated and softened a number of times without suffering any basicalteration in characteristics, provided heating is below thedecomposition temperature of the polymer. Examples of thermoplasticpolymers include, by way of illustration only, polyolefins, polyesters,polyamides, polyurethanes, acrylic ester polymers and copolymers,polyvinyl chloride, polyvinyl acetate, etc. and copolymers thereof.

The term “asphalt” is used herein to mean asphalt before it is mixedwith any aggregate.

The term “asphalt composite” is used herein to mean asphalt that ismelted and mixed with a polymer film outer coating of an asphalt packet.The asphalt composite is mixed with aggregate to form an asphalt mix.

The terms “asphalt mix” and its variations, including but not limitedto, hot mix asphalt, warm mix asphalt, and cold mix asphalt, is usedherein to mean a mixture of asphalt and/or asphalt composite with anaggregate gradation to form asphalt pavement used in constructing andrepairing roads, parking lots, airfields and the like.

The term “warm mix asphalt” is used herein to mean hot mix asphalt whichhas been modified with additives to lower its paving temperature by 20°F. to 50° F. cooler than regular hot mix asphalt. The additive lowersthe viscosity of the liquid asphalt.

The term “hot mix asphalt” is a generic term used herein to mean atraditional asphalt that is mixed with appropriate aggregate and heatedto between about 280° F. and about 340° F. to make an asphalt mix.

The term “cold mix asphalt” is used herein to mean asphalt withadditives, including but not limited to solvents, mixed therein tosoften the asphalt at ambient temperatures for paving potholes with theadditives being configured to at least partially evaporate allowing theasphalt mix formed with the cold mix asphalt to harden.

The term “asphalt pavement” is used herein to mean pavement and pavementrepairs created by an asphalt mix.

The term “aggregate” is used herein to mean all the sizes of stone usedin an asphalt mix which can include but is not limited to granular stoneof size of about 200 mesh up to stones generally about ¾ of an inchacross its longest axis.

The term “aggregate gradation” as used herein has the same meaning asthe term “aggregate” and is used herein to mean the specific sizedistribution of stone used in an asphalt mix which can include but isnot limited to granular stone of size of about 200 mesh up to stonesgenerally about ¾ of an inch across its longest axis.

The terms of “degrade,” “degradation,” “degrading,” or the like, as usedherein in conjunction with the terms asphalt, asphalt composite, hot mixasphalt or asphalt mix are used to identify when asphalt loses itsadhesive property and flexibility due to exposure to excess temperaturethat causes resins and petroleum by-products within the asphalt toevaporate from the asphalt which can eventually render the asphalt mixand pavement produced from the degraded asphalt unusable.

The terms “rectangular packet,” “rectangular-shaped packet,” or thelike, as used herein in conjunction with the terms asphalt or asphaltpacket means asphalt packets that have the general shape of ahyperrectangle having height dimension, a length dimension, and a widthdimension.

Asphalt can generally be considered a combination of resins, oil andpetroleum by-products, and asphaltenes. These combine in a colloidalsystem. Asphaltenes are not insoluble in non-polar solvents whereas theresins and petroleum by-products are (sometimes referred to as maltenesor petrolenes). When heated to high temperatures the resins andpetroleum by-products are somewhat volatile and can be boiled off. Thisreduces the adhesive and flexible properties of the asphalt and canrender it unusable if too much of the volatiles are boiled off due toexcessive time and temperature. The flash point of asphalt is usuallylisted as 450° F. or more. This can vary according to the particulargrade of asphalt. That is the temperature at which the volatiles canbecome combustible in the presence of a spark or flame. Therefore, theprocessing temperatures of asphalt are generally kept below 450° F.

Liquid asphalts are generally stored and transported at temperaturesaround about 300° F. to about 320° F. to keep them flowable. As seenfrom the Table 1, the viscosity of PG 76-22 asphalt is about 2600 cp at290° F. and increases rapidly to over 6100 cp at 250° F. Generally,after combining with aggregate the maximum acceptable temperature forhot mix (asphalt mixed with aggregate) is 375° F. If heated above thistemperature for very long, the asphalt will turn brown and loose itsadhesive properties and its flexibility which will render it useless asa paving material.

A test to measure the loss of flexibility of the asphalt is described inASTM D2872 as the Rolling Thin Film Oven test. This test measures theaging characteristics of the asphalt as an indication of its oil contentand degree of degradation. In general, it is important to keep thetemperature of the asphalt within about 320° F. when mixed withaggregate to minimize degradation and yet maintain its viscosity lowenough for good compaction of the mix during the paving operation.

The use of proper sized and shaped packets which melt quickly when mixedwith aggregate and heated in a rotating cylinder is important to coatthe aggregate as it comes up to a paving temperature of about 300° F. toabout 320° F. within minutes. This assures the production andperformance of good mix and the minimization of loss of volatiles andconsequent degradation of the asphalt hot mix.

To address the issues related to storage and preparation of a hot orwarm mix asphalt, the present disclosure provides the formation of smallpackets of asphalt by extruding the molten asphalt through a forming dyeand simultaneously co-extruding a polymeric coating around the body ofthe asphalt extrusion. An incremental length of that co-extrudingasphalt polymer structure can be heat-sealed and then cut into segments,or packets, forming sealed ends and thus packets which fully encapsulatethe sticky asphalt with a non-sticky robust polymeric coating which isflexible and will not crack upon deformation of the packet.

When cooled, this coating forms a rectangular shape for packaging, asshown in FIG. 3 (compared to pellets) with the bulk of the asphalt inthe middle of the structure. This packet will allow the asphaltparticles to be packaged in a container and will be free flowing. Thenon-tacky polymeric coating can be a material fully compatible with theasphalt when reheated, thus having no negative effect on the performanceof the asphalt mixture. Also, the thickness of the polymeric coating canbe controlled to provide robust packets of non-sticky material which arefree flowing, separate, and can be easily uniformly mixed with theasphalt to form a high-quality asphalt hot mix.

In forming the asphalt packets, the size of the packets can be kept thinto create a higher surface to volume ratio and smaller cross-sectionalarea to allow the asphalt packet to melt quickly and coat the aggregatewithout burning or degrading the asphalt. It has been found that thehigher the surface to volume ratio of the asphalt packets, the fasterthe melting rate.

In addition to HMA, the asphalt packets as disclosed herein can also beused in the production of warm mix asphalt. Using asphalt packets makethe production of warm mix asphalt much easier than can be done withpelletized asphalt that has a hard powder coating because the formationof the packet is less affected by the viscosity of the asphalt thanformation of the pellets and the polymer film coating is more flexibleand will not crack upon deformation of the packet as compared to thehard powder coating used in pelletized asphalt. Warm mix asphalt isasphalt that has additives mixed in the liquid binder asphalt such thatthe viscosity of the hot liquid asphalt is lowered substantially whilein the liquid phase thus allowing the liquid asphalt to better coat theaggregate at a lower temperature than hot mix asphalt by about 20° F. to40° F. This saves energy and lowers volatile organic compounds andconsequent smells of the hot mix asphalt. The warm mix liquid asphalt iseasy to process into packets due to the process which is not assensitive to melt viscosity. The asphalt packets disclosed herein can beused to store a warm mix asphalt material at ambient temperature whichcan later be heated and mixed to make a high quality warm mix asphalt.

To function properly in the formation of an asphalt mix, the asphaltpackets can have a surface-to-volume ratio sufficiently high so thatwhen the packets are mixed with the appropriate aggregate and exposed toheat, the asphalt melts quickly enough to liquefy and uniformly coat theaggregate as the composite mix reaches the full proper temperature. Thisensures an even coating of the aggregate while not excessively degradingthe asphalt due to thermal oxidation due to excessive heat.

The asphalt packets disclosed herein have advantages over asphaltpellets that include having a more flexible and robust coating or skinlayer that will not crack if the asphalt packets are deformed whilebeing packaged and stored. The thickness of the packets and the surfacearea to volume ratio can be better controlled to provide a more robustasphalt package that can liquefy and uniformly coat the aggregate as thecomposite mix reaches the full proper temperature. The asphalt packetscan be packaged without the aggregate and packaged and stored to a undera reasonable weight pressure without interlocking or sticking togetheras compared to the asphalt pellets described above. Further, asphaltpackets can be manufactured more simply with less complicated equipmentand less expensively than asphalt pellets.

Unlike adhesive sachets that are used to hold polymeric adhesives, sizeand shape of asphalt packets are more critical due to the composition ofthe material being held in the packet. Polymeric adhesive sachetscontain homogeneous polymeric adhesives that have homogeneous meltingpoints, such that if a melting temperature is maintained will notdegrade even after melting. Asphalt is comprised of compounds ofasphaltenes and maltenes that can include a wide variety of differentelements depending on the crude oil from which the asphalt derives,containing alcohol, carboxyl, phenolic, amine, thiol, and otherfunctional groups. Asphalt may be regarded as colloids of asphaltenemicelles dispersed in maltenes. Due to the composite nature of asphalt,exposure to a heat source that is hot enough to melt the asphalt withoutigniting the asphalt can begin to degrade the asphalt if the exposure istoo long in duration. This degradation can be at least partly due todifferent compounds with different properties from other compoundswithin the composition of the asphalt beginning to deteriorate and burnoff as the melted portion of the asphalt is continued to be exposure tothe high heat to melt the unmelted portions of the asphalt packet. Ifthe temperature from the heat source is too high, the melted asphaltheats up too much while the rest of the asphalt packet is still beingmelted, the portions of the asphalt that have already melted will beginto degrade. This problem can be compounded if the asphalt packet is toolarge. If the temperature from the heat source is too low, the melt timeof the packets increases too much in the rotating mixer as the asphaltpackets are heated with the aggregate, the substantially longer melttime of the lower surface/volume ratio packets (i.e., larger packets)will cause coagulation of the packets into large sticky balls due toexcessive melt time and insufficient heat and thus consequent longerresidence time required to heat the mix. This coagulation will preventuniform coating of the aggregate and thus unacceptable quality of hotmix.

Also, since the relative weight percent of the asphalt to aggregate inthe mix is about 6 percent, then at 6 percent by weight, since theaggregate specific gravity is heavier (about 2.2) than the asphalt(about 1.0), the volume of asphalt is about 12.4 percent of theasphalt/aggregate mix by volume. Therefore, as the weight per packetdecreases (i.e., packets with higher surface area/volume ratio), thenumber of packets increases to maintain the 12.4 percent volume. Thislarger number of the smaller packets will result in a more uniform mixas well as a faster melting time as compared to larger asphalt packetshaving lower surface area/volume ratio. Therefore, there is an optimumrange of surface/volume ratio of the packets of approximately 10 to 25or greater to create uniform hot mix in the rotating mixer.

Referring to FIGS. 1A and 1B, a non-tacky asphalt packet generallydesignated 10, is provided. The non-tacky asphalt packet can comprise aninner volume of asphalt 12 and a polymer film outer coating 14encapsulating the volume of the asphalt 12. The polymer film outercoating 14 can form an outer surface 16 of the asphalt packet 10. Thepolymer film outer coating 14 can comprise a polymer that is non-tackyat ambient temperatures, for example, between about 45° F. and about120° F. The asphalt packet 10 can be produced in a variety of ways asexplained further below. In some embodiments, as shown in FIGS. 1A and1B, the asphalt packet 10 can be formed through a coextrusion processthat extrudes the polymer film outer coating 14 around the asphalt 12that includes a sealing process that forms ends 18 of the asphalt packet10 that comprise the polymer film outer coating 14 to seal the asphalt12 within the asphalt packet 10. The asphalt packet 10 can thus have aheight H, a width W, a length L. As shown in FIG. 1B, the height H ofthe asphalt packet 10 can form a thickness t of the smallest dimensionaldistance. The thickness t of the smallest dimensional distance can bethe thickness of any dimension that has the smallest dimensionalmeasurement of the asphalt packet 10. The rate at which the asphaltpacket 10 will melt without degrading within an asphalt mixer can be atleast partially dependent on this measurement.

The asphalt 12 can comprise the majority of the weight of the asphaltpacket such that the properties of asphalt advantageous for producingasphalt pavement are not compromised. For example, in some embodiments,the asphalt 12 can comprise at least about 85% of the non-tacky asphaltpacket by weight. In some embodiments, the asphalt 12 can comprise atleast about 90% of the non-tacky asphalt packet by weight. In someembodiments, the asphalt 12 can comprise virgin asphalt material, forexample when making a hot mix asphalt for use in asphalt pavement thatneeds to have a high strength to withstand high weight pressures and/orrepeated use such as in airfields and interstate highways. In someembodiments when the asphalt packets are to be used in a warm asphaltmix, the asphalt can comprises a warm mix asphalt material.

The polymer film outer coating 14 is compatible with the asphalt 12 suchthat as the polymer film outer coating 14 is melted with the asphalt 12,an asphalt composite is formed, the polymer of the polymer film coating14 does not diminish the performance of the asphalt composite formed bythe mixture of the polymer film outer coating 14 and the asphalt 12. Thepolymer film outer coating 14 can thus comprise a compatible non-tackypolymeric coating which is fully compatible with the asphalt 12 when thepolymer film outer coating 14 and the asphalt 12 are melted into liquidform. For example, the polymer film outer coating can compriseethylene-vinyl acetate (EVA) or polymeric blends that include EVA,styrenic block copolymers (SBC) or polymeric blends that include SBC,styrene-butadiene-styrene (SBS) block copolymers orstyrene-ethylene-butylene-styrene (SEBS) polymers or polymeric blendsthat include SBS and/or SEBS. Further, some combination polymeric blendsof these polymers listed above can used as the polymer film outercoating 14. The polymer film outer coating 14 can have a thickness t_(f)that can prevent the asphalt 12 from leaking therethrough even whenplaced under weighted pressure and keeps the asphalt contained withinthe polymer film outer coating 14. For example, in some embodiments, thepolymer film outer coating 14 can have a thickness t_(f) of betweenabout 0.001 inches and about 0.01 inches (between about 1 mil and about10 mils).

The asphalt packet 10 comprising the polymer film outer coating 12 andthe volume of asphalt 12 can have a surface-to-volume ratio that permitsthe complete melting of the polymer film outer coating 14 and theasphalt 12 upon reaching a melting point of asphalt 12 in a range oftime such that the polymer film outer coating 14 and asphalt 12 liquefywithout degradation of the asphalt composite during a liquefactionprocess.

For example, the surface-to-volume ratio of the asphalt packet 10 can besuch that, when a plurality of the non-tacky asphalt packets 10 aredispersed in an aggregate mixture in a mixer and heated to a mixingtemperature, the plurality of asphalt packets 10 melt and coat theaggregate uniformly with the asphalt composite as the aggregate reachesthe maximum mix temperature as measured at the asphalt mix and prior todegradation of the asphalt composite due to prolonged exposure toexcessive temperature. For example, in some embodiments, the mixtemperature can range between about 260° F. and about 340° F. In someembodiments, the mix temperature can range between about 280° F. andabout 320° F. The range of time that the asphalt can be exposed to beheated to such temperatures and thorough melt before degradation occurscan vary. In some embodiments, the range of time can be between about 20seconds and about five (5) minutes as explained further below.

To allow for a thorough liquefaction of the asphalt packet withoutdegradation of the asphalt composite formed, the surface-to-volume ratioof the asphalt packets 10 can be at least about 10. In some embodiments,the surface-to-volume ratio of the asphalt packets 10 can be betweenabout 15 and about 30. In some embodiments, the surface-to-volume ratioof the asphalt packets 10 can be greater than about 17. In someembodiments, the surface-to-volume ratio of the asphalt packets 10 canbe greater than about 20. At that temperature and surface area-to-volumeratio, the packet can be fully melted and is available to uniformly coatthe aggregate in the rotating drum to form the required hot mix forpaving.

In combination with the surface-to-volume ratio, the thickness asmeasured across the smallest dimensional distance of the asphalt packet10 can impact the ability of the asphalt packet to thoroughly meltbefore degradation occurs. Thus, depending on the orientation of thepacket, the thickness as measured across the smallest dimensionaldistance of the asphalt packet can be a height, length or width of someasphalt packets or a diameter of some asphalt packets depending on theshape of the asphalt packet. In the embodiment shown in FIGS. 1A and 1B,as stated above, the height H of the asphalt packet 10 comprises thethickness t of the smallest dimensional distance. While the asphaltpacket 10 is not exactly a rectangular-shaped packet, the measurementsof the surface-to-volume ratio of the packet 10 are close enough incalculation with the surface-to-volume ratio of a similarly dimensionedrectangular-shaped packet with the same height, length and width that,for the purposes of this disclosure, the asphalt packet 10, is generallyconsidered a rectangular shaped asphalt packet.

When the asphalt packets at ambient temperature are exposed to hot airin a rotating mixing cylinder its temperature will begin to riseaccording to the laws of heat transfer. Assuming the convective transferis large, the limiting factor to heating the packets quickly is theconductive heat transfer. Referring to FIG. 2, an asphalt packet 10 isprovided that can help explain conductive heat transfer that can helpdetermine the size and shape of the asphalt packet that will prevent theasphalt from degrading or burning while the asphalt inside melts. Thepacket 10 will conduct heat from the hot gas and also the contact withthe hot rotating cylinder and heated aggregate in accordance withEquation (A) expressed as

O=K×A(T _(s) −T _(c) /x/2)  Equation (A)

-   -   Where:        -   O=Heat Transfer to Packet on Each Side (BTU/minute)        -   K=Thermal Conductivity of Asphalt        -   A=Area        -   x=Thickness of Dimension having the Smallest Dimensional            Distance        -   T_(s)=Temperature of Surface        -   T_(c)=Temperature of Center

The amount of heat required to heat the packet from ambient to about320° F. is expressed by the equation B:

Q=M×Cp×ΔT  Equation (B)

-   -   Where:        -   Q=BTU        -   M=Mass of the Packet        -   Cp=Specific Heat of Asphalt        -   ΔT=Temperature Change (ending temperature minus beginning            temperature for example 320° F.-80° F.)

As seen from Equation A, the smaller the minimum dimension “x” and thelarger the area, A, the higher the rate of heat transfer, Q, andconsequently the less time is required to provide the total BTUs (Q)from Equation B required to reach the 320° F. service temperature acrossthe whole asphalt packet 10.

The asphalt packets 10 can be different shapes to achieve the desiredsurface area to volume ratio. For example, the shape of the asphaltpackets 10 can be spherical, ellipsoidal, ovoidal, rectangular,rectangular, cylindrical with tapered ends, or the like. For example,the asphalt packets 10 can be rectangular with rounded or tapered sidesand ends, such as a pillow-shape or a sachet. For some embodiments ofthe asphalt packet 10 that are in the shape of a sachet such as thoseshown in FIG. 1, the asphalt packet 10 can have a width of about 0.5inches, a height of about 0.2 inches, and a length of about 0.75 inchesso that the smallest dimensional distance is the height. For someembodiments of the asphalt packet 10 that are in the shape of a sachet,the asphalt packet 10 can have a width of about 0.5 inches, a height ofabout 0.15 inches, and a length of about 0.75 inches. For someembodiments of the asphalt packet 10 that are in the shape of a sachet,the asphalt packet 10 can have a width of between about 0.3 and about0.5 inches, a height of about 0.1 and about 0.2 inches, and a length ofabout 0.50 to about 1.5 inches. For example, in one embodiment, theasphalt packet 10 can have a surface area to volume ratio of 24 and awidth W of about 0.50 inch by length L of about 1.50 inches and athickness of about 0.120 inches.

Other examples of differently shaped asphalt packets are shown in FIGS.3A-7B and examples of how the surface area to volume for each areprovided. Referring to FIGS. 3A and 3B, the sachet-shaped asphalt packet30 is provided that can also comprise an inner volume of asphalt 12 anda polymer film outer coating 14 encapsulating the volume of the asphalt12. The polymer film outer coating 14 can form an outer surface 16 ofthe sachet-shaped asphalt packet 30. The polymer film outer coating 14can have a thickness t_(f) between about 0.001 inches and about 0.01inches (between about 1 mil and about 10 mils).

The surface area-to-volume ratio for a sachet-shaped asphalt packet 30can be calculated based on the equations (C), which is derived fromequations (D) and (E) below.

$\begin{matrix}{{S\; {A/V}} = \frac{2\lbrack {{W \times L} + {H \times L} + {2( {C \times W} )} + {h \times H}} \rbrack}{W \times H \times ( {h + L} )}} & {{Equation}\mspace{14mu} (C)} \\{{S\; A} = {{2( {W \times L} )} + {2( {H \times L} )} + {4( {C \times W} )} + {2( {h \times H} )}}} & {{Equation}\mspace{14mu} (D)} \\{V = {( {W \times H} )( {h + L} )}} & {{Equation}\mspace{14mu} (E)}\end{matrix}$

-   -   Where:    -   SA=Surface Area    -   V=Volume    -   W=Width of the Sachet-Shaped Asphalt Packet 40    -   L=Length of the Sachet-Shaped Asphalt Packet 40    -   H=Height of the Sachet-Shaped Asphalt Packet 40    -   C=Length of the Sloping End Portions of the Sachet-Shaped        Asphalt Packet 40    -   h=Linear Length of the End Portions of the Sachet-Shaped Asphalt        Packet 40

Referring to FIGS. 4A and 48, the spherical-shaped asphalt packet 40 cancomprise an inner volume of asphalt 12 and a polymer film outer coating14 encapsulating the volume of the asphalt 12. The polymer film outercoating 14 can form an outer surface 16 of the spherical-shaped asphaltpacket 40. The polymer film outer coating 14 can have a thickness t_(f)between about 0.001 inches and about 0.01 inches (between about 10 milsand about 100 mils). The surface area-to-volume ratio for aspherical-shaped asphalt packet 40 can be calculated based on theequation (F) below.

$\begin{matrix}{{S\; {A/V}} = {\frac{4 \times \pi \times r^{2}}{{4/3} \times \pi \times r^{3}} = \frac{3}{r}}} & {{Equation}\mspace{14mu} (F)}\end{matrix}$

-   -   Where:    -   SA=Surface Area    -   V=Volume    -   r=The Radius of the Spherical Packet 30 where the Radius is        equal to one half of the Diameter D

The surface-to-volume ratio of the spherical-shaped asphalt packet 30can vary depending on the diameter D of the spherical-shaped asphaltpacket 30. Examples of such surface-to-volume ratio of thespherical-shaped asphalt packet 30 are shown in Table 1.

TABLE 1 Surface-to-Volume Ratio of Spherical-Shaped Asphalt PacketsDiameter of Spherical-Shaped Asphalt Surface-to-Volume Ratio Packets(inches) (1/inch) 0.125 48 0.250 24 0.50  12

Referring to FIGS. 5A and 5B, the cylindrical-shaped asphalt packet 50can comprise an inner volume of asphalt 12 and a polymer film outercoating 14 encapsulating the volume of the asphalt 12. The polymer filmouter coating 14 can form an outer surface 16 of the cylindrical-shapedasphalt packet 50. The surface area-to-volume ratio for acylindrical-shaped asphalt packet 50 can generally be calculated basedon the equation (G) below.

$\begin{matrix}{{S\; {A/V}} = \frac{4}{D}} & {{Equation}\mspace{14mu} (G)}\end{matrix}$

-   -   Where:    -   SA=Surface Area    -   V=Volume    -   D=The Diameter of the Cylindrical-Shaped Asphalt Packet 50

The surface-to-volume ratio of the cylindrical-shaped asphalt packet 50can vary depending on the diameter D of the cylindrical-shaped asphaltpacket 50. Examples of such surface-to-volume ratio of thecylindrical-shaped asphalt packet 50 are shown in Table 2.

TABLE 2 Surface-to-Volume Ratio of Cylindrical-Shaped Asphalt PacketsDiameter of Cylindrical-Shaped Asphalt Surface-to-Volume Ratio Packets(inches) (1/inch) 0.125 32 0.250 16 0.50   8

Referring to FIGS. 6A and 6B, the square bar-shaped asphalt packet 60can comprise an inner volume of asphalt 12 and a polymer film outercoating 14 encapsulating the volume of the asphalt 12. The polymer filmouter coating 14 can form an outer surface 16 of the square bar-shapedasphalt packet 60. The surface area-to-volume ratio for a squarebar-shaped asphalt packet 60 can generally be calculated based on theequation (H) below.

$\begin{matrix}{{S\; {A/V}} = \frac{4}{E}} & {{Equation}\mspace{14mu} (H)}\end{matrix}$

-   -   Where:    -   SA=Surface Area    -   V=Volume    -   E=The Length of Each Side of the Square Bar-Shaped Asphalt        Packet 60

The surface area-to-volume ratios calculations a similar to thecylindrical-shaped asphalt packet 50 for different sized packets asshown in Table 3.

TABLE 3 Surface-to-Volume Ratio of Square BarShaped Asphalt PacketsDiameter of Square Bar-Shaped Asphalt Surface-to-Volume Ratio Packets(inches) (1/inch) 0.125 32 0.250 16 0.50   8

Referring to FIGS. 7A and 7B, the rectangular-shaped asphalt packet 70can comprise an inner volume of asphalt 12 and a polymer film outercoating 14 encapsulating the volume of the asphalt 12. The polymer filmouter coating 14 can form an outer surface 16 of the rectangular-shapedasphalt packet 70. The surface area-to-volume ratio for arectangular-shaped asphalt packet 70 can generally be calculated basedon the equation (H) below.

$\begin{matrix}{{S\; {A/V}} = \frac{2( {N + 1} )}{N \times E}} & {{Equation}\mspace{14mu} (H)}\end{matrix}$

-   -   Where:    -   SA=Surface Area    -   V=Volume    -   E=The Width of Shorter Side of the Rectangular-Shaped Asphalt        Packet 70    -   N=The Ratio of the Width of the Longer Side divided by the Width        of the Shorter Side of the Rectangular-Shaped Asphalt Packet 70    -   N×E=The Width of Longer Side of the Rectangular-Shaped Asphalt        Packet 70

Referring back to FIG. 1, the surface-to-volume ratio of the asphaltpackets 10 can be such that the asphalt packet 10 fully melts withinfive minutes when exposed to a heat of up to about 450° F. In someembodiments surface-to-volume ratio of the asphalt packets 10 can besuch that the asphalt packet 10 fully melts within in two minutes whenexposed to a heat of up to about 450° F. In some embodiments, thesurface-to-volume ratio of the asphalt packets 10 can be such that theasphalt packet 10 fully melts within in one minute when exposed to aheat of up to about 450° F. In some embodiments, surface-to-volume ratioof the asphalt packets 10 can be such that the asphalt packet 10 fullymelts within 30 seconds when exposed to a heat of up to about 450° F.

The polymer film outer coating 14 can have a thickness such that aplurality of the asphalt packets 10 are storable at ambient temperaturefor at least 5 years without degrading the polymer film outer coating 14and the asphalt 12 to permit the asphalt packets 10 to still bedispersable into a heater or a heated mixer in a friable manner. In thismanner, even after storage, a plurality of the asphalt packets 10 can bemixed with an appropriate aggregate to form a mix gradation with a %weight ratio for the asphalt packets 10 being about 3% to about 10% ofweight of the mix gradation and heated to a mix temperature of betweenabout 260° F. to about 340° F. The plurality of asphalt packets liquefyand uniformly coat the aggregate to produce a high quality asphalt hotmix for paving roads and airfields. The asphalt packets are mixable withan appropriate aggregate and heated in an appropriate mixer can producehigh quality hot mix in remote locations in less than about 20 minutes.For example, in some embodiments, a plurality of the asphalt packets 10can be packed at least 20 inches deep in a container under ambientconditions and can then be stored for up to 1 year or more with theplurality of asphalt packets 10 maintaining their integrity without thepolymer film outer coatings 14 of the asphalt packets 10 beingcompromised.

Thus, as disclosed herein, an asphalt packet 10 can have a non-tackyouter surface and a size and shape that allows the asphalt packet 10 tofully melt into an asphalt composite before degradation of the asphaltor asphalt composite begins. The asphalt packet 10 can comprise anasphalt 12 that is at least 85% by weight of high-quality virgin asphaltthat comprises an inner volume and a polymer film outer coating 12 thatencapsulates the volume of the asphalt. The polymer film outer coating10 can be non-tacky at ambient temperatures and can permit stacking of aplurality of asphalt packets under weight without causing the packets toagglomerate. The polymer film outer coating 14 and the volume of asphalt12 can have a size and shape to create a surface-to-volume ratio thatpermits the complete melting of the polymer film outer coating 14 andthe asphalt 12 into a liquid form of an asphalt composite when heated tobetween about 260° F. and about 340° F. before the asphalt compositebegins to degrade. These asphalt packets 10 can fully melt within fiveminutes when exposed to a heat of up to about 450° F. In someembodiments, these asphalt packets 10 can fully melt within in twominutes when exposed to a heat of up to about 450° F. In someembodiments, these asphalt packets 10 can fully melt within in oneminute when exposed to a heat of up to about 450° F. In someembodiments, these asphalt packets 10 can fully melt within 30 secondsor less when exposed to a heat of up to about 450° F.

Thus, as provided above, the non-tacky asphalt packet can have a surfacelayer that comprise a continuous layer of polymer compatible with theasphalt, and which has a surface-to-volume ratio which in the presenceof heat makes the asphalt melt in an adequately short time such thatwhen dispersed in an aggregate mixture allows the asphalt to melt andthe asphalt to coat the aggregate uniformly as the aggregate reaches themaximum mix temperature, and prior to degradation of the asphalt due toexcessive temperature.

The asphalt packet can comprises a non-tacky outer coating layer thatenvelopes an asphalt preparation that comprises the center of theasphalt packet. The asphalt packet can have a surface-to-volume ratiogreater than about 10. The non-tacky outer coating layer can comprise acompatible non-tacky polymeric coating of one or more thermoplasticpolymers which is fully compatible with the asphalt liquid when melted.For example, the one or more thermoplastic polymers can be meltablepolymers in a temperature range of between about 200° F. and about 300°F. In some embodiments, the one or more thermoplastic polymers that canbe used as the outer coating layer can comprise at least one ofethylene-vinyl acetate (EVA), styrenic block copolymers (SBC),styrene-butadiene-styrene (SBS) block copolymers andstyrene-ethylene-butylene-styrene (SEBS) polymers, such as those soldunder the tradename of KRATON™.

The non-tacky outer coating layer fully encapsulates the tacky asphaltwith the continuous non-tacky outer coating layer making the structurenon-tacky at ambient temperature. The non-tacky outer coating layer cancomprise a small percentage of the overall mass of the asphalt packetwith at least about 80% of a standard asphalt material comprising themajority of the majority of the mass of the asphalt packet. Whenuniformly dispersed in an appropriate gradation of stone aggregate andcan be stored at ambient temperature for at least 5 years and then bedispersed into a heater in a free-flowing manner.

When mixed with an appropriate aggregate gradation with a % weight ratioof about 3% to about 10%, the asphalt packets can be uniformly mixed andheated to a mix temperature of about 280° F. to 320° F. to produce ahigh quality asphalt hot mix which can be used for paving roads andairfields. By using asphalt packets as described herein with the correctaggregate mixture and heated in an appropriate mixer, a high-quality hotmix asphalt can be produced in remote locations in less than 20 minutes.The asphalt packets can be packaged in containers at least 20 inchesdeep under ambient conditions and remain free flowing for 1 year ormore.

The proper aggregate gradation can be produced either in pre-measuredbatch form or at the mix site. A precisely accurate ratio of asphaltpackets must be mixed with the aggregate in a well distributed mix. Thepackets should be in free-flowing form to accommodate a well distributedaccurate ratio of the mixture. By free-flowing, it is meant that when aplurality of packets is distributed into a heated mixer that they do notstick together and tumble over each other as the asphalt packets arepoured from a container into a mixer. The asphalt/aggregate mixture canbe heated in the heated mixer to a uniform mix temperature of about 300°F. When heating in the mixer, the asphalt packets melt at a specificrate so as to properly coat the full aggregate gradation withoutoverheating. If overheating occurs, it will cause the asphalt binder tooxidize and degrade thus loose part of its adhesive and flexibilityproperties, which are required for a good asphalt mix to produce a goodquality asphalt pavement.

Part of the importance of this melting rate is related to the steeptemperature viscosity curve of the asphalt as illustrated in the Table 4below. Low viscosity is required for proper coating and the lowviscosity is achieved in the range of about 290° F. to 300° F. as shownbelow for the PG 76-22 grade of asphalt commonly used for airfieldpavement and repairs.

TABLE 4 Temperature Relative to Viscosity of PG 76-22 Grade AsphaltTemperature (° F.) Viscosity (Centipose) 180 200,000 200 74,000 2506,100 290 2,600

In order to function properly in the mix, the asphalt packets can havespecific properties which allow them to produce high quality hot mix.For example, the packets can be composed of at least about 85% to about90% of an approved grade of asphalt and be designed according to aproper Job Mix Formula (which is an industry term that specifies thespecific aggregate gradation and the percentage asphalt for a specificasphalt pavement design) for good pavement performance. The outersurface of the packets can be non-tacky so as to be easily handled andto disperse well within the aggregate gradation at ambient temperature.The asphalt packets should melt within the time frame required to heatthe aggregate in a heated mixer such that, as the aggregate reaches itsworking temperature of about 300° F., the asphalt viscosity is reducedto a sufficiently low value to provide good and uniform coating for theaggregate from fines to coarse stone sizes. The asphalt packets shouldmelt sufficiently within a proper time to reduce the asphalt viscosityto a low value as shown above. The asphalt packets must be thermallystable with a non-tacky surface so as to withstand storage long term atambient temperatures without sticking together or flowing together andto remain free-flowing for use in an appropriate heated mixer. Dependingon how the asphalt packets are packaged, the asphalt packets should beable to withstand storage long term under weigh pressure and at ambienttemperatures without sticking together or flowing together.

In order to meet the criterion of melting at the rate the aggregate isheating up, which requires a short melting time, it was discovered thatthe asphalt packets must be small in size and consequently have a largesurface to volume ratio to melt rapidly to a low viscosity as theaggregate heats up to the working temperature.

Asphalt packets of different sizes were tested. Asphalt packets werefabricated comprising a thin layer of polyethylene plastic that formedthe outer surface of the asphalt packet. These asphalt packets had apolymer film outer coating having a film thickness of about 0.01 inches(about 1 mils) and comprised an inner volume of PG 76-22 asphalt. Beforetesting, the asphalt packets were cooled to about 62° F. Each asphaltpacket was attached to a vertical board. For the rectangle shapedasphalt packets tested, the asphalt packets with the longest dimension(length) extended parallel to the surface of the vertical board with theshortest dimension (height, which, in these embodiments, comprise thethickness of the smallest dimensional distance) positioned perpendicularto the surface of the vertical board. A commercial butane torch waspositioned about 7 inches from each sample asphalt packet such that theflame of the torch was about perpendicular to the surface of thevertical board. The melting times were measured from the beginning theheat cycle, when the flame of the torch was lit, until the asphalt wasfully melted. The results are provided below in Table 5. As seen fromthe above data, the smaller asphalt packet shape, i.e., higher surfacearea/volume, tend to melted faster.

TABLE 5 Volumetric Dimensions of Asphalt Container Shape Relative toMelt Time Volumetric Dimensions* Surface Area/ in inches Volume AsphaltContainer (D**) or Melt Time Ratio Shape (H × W × L)*** (seconds)(1/inch) Spherical Packet 0.25  21 24.0 Rectangular Packet 1/8 × 1/2 ×3/4  50 22.6 Rectangular Packet 1/4 × 1/2 × 3/4 114 14.7 RectangularPacket 3/8 × ½ × 3/4 127 12 Rectangular Packet 1/2 × 1/2 × 3/4 151 10.7Cube Packet 1 × 1 × 1 583 6 *Dimensions in inches are provided for**Diameter or ***Height by Width by Length for the various shapedasphalt packets.

Thus, referring back to FIG. 1, in some embodiments, the asphalt packet10 can have a height of about ⅛ inches (about 0.125 inches), a width ofabout ½ of an inch (about 0.5 inches), and a length of about ¾ inches(about 0.75 inches) such that surface area-to-volume ratio is about the22.6 and the thickness (the height in such an embodiment) of smallestdimensional distance is about 0.125 inches. For some embodiments, theasphalt packet 10 can have a height of about ¼ inches (about 0.25inches), a width of about ½ of an inch (about 0.5 inches), and a lengthof about ¾ inches (about 0.75 inches) such that surface area-to-volumeratio is about the 14.7 and the thickness (the height in such anembodiment) of smallest dimensional distance is about 0.25 inches. Forsome embodiments, the asphalt packet 10 can have a height of about ⅜inches (about 0.375 inches), a width of about Y of an inch (about 0.5inches), and a length of about ¾ inches (about 0.75 inches) such thatsurface area-to-volume ratio is about the 12.0 and the thickness (theheight in such an embodiment) of smallest dimensional distance is about0.375 inches. For some embodiments, the asphalt packet 10 can have aheight of about ½ inches (about 0.5 inches), a width of about ½ of aninch (about 0.5 inches), and a length of about ¾ inches (about 0.75inches) such that surface area-to-volume ratio is about the 10.7 and thethickness (either the height or the width in such an embodiment) ofsmallest dimensional distance is about 0.5 inches.

Referring to FIG. 10, the graph provided there are based on themeasurements presented in Table 5 above, where the surface/volume ratioof the asphalt packet is plotted against the melt time of the asphaltpackets based on the testing methods described above. The graphillustrates that as the surface/volume ratio of the asphalt packetdecreases (i.e., as the packet size increases), the melt time increasesalmost exponentially. The data for table is taken by holding thetemperature of the heat supply constant at about 400° F. It the heattemperature is increased too high, above the ignition temperature of theasphalt, about 450° F. in many cases, the asphalt will ignite and catchon fire as well as degrade rapidly. Therefore, the maximum temperatureof the heat is limited and as seen in FIG. 10 the melt time increasesdramatically as the surface to volume ratio decreases below 10. Exposureto a heat source that is hot enough to melt the asphalt without ignitingthe asphalt will begin to degrade the asphalt if exposure is too long induration. This is at least partly due to the petroleum by-productswithin the composition of the asphalt begin to deteriorate and burn offas the melted portion of the asphalt is continued to be exposure to thehigh heat to melt the unmelted portions of the asphalt packet. The melttime of the 1 inch×1 inch×1 inch cube while being exposed to the heatsource for over 8 minutes resulted in a degradation of the asphalt Inthe test results presented above, for the asphalt packets having amelting time under the temperature conditions of the test of about three(3) minutes or less resulted the asphalts that did not show signs ofdegradation. For similar mixing environments where enough heat isprovided to sufficiently melt the asphalt without excessive coagulationbut not too high of a temperature to ignite the asphalt, it is believedthat a melt time of about five (5) minutes or under can provide auniform coating of aggregate without degradation of the asphaltoccurring.

Since the relative weight percent of the asphalt to aggregate in the mixis about 6 percent, then at 6 percent by weight, since the aggregatespecific gravity is heavier (about 2.2) than the asphalt (about 1.0),the volume of asphalt is about 12.4 percent of the asphalt/aggregate mixby volume. Therefore, as the weight per packet decreases, the number ofpackets increases to maintain the 12.4 percent volume. For example, inFIG. 10, the 12.4 percent asphalt in the mix for a 1-inch cube ofasphalt (1.0 cubic inch) equates to about 21.3 packets (0.047 cubic incheach) of the ⅛×½×¾ packet shown in Table 5. This larger number of thesmaller packets will result in a more uniform mix with less opportunityfor degradation of the asphalt as it melts as well as a faster meltingtime. Therefore, there is an optimum range of surface/volume ratio ofthe packets of approximately 10 to 25 or greater to create uniform hotmix in the rotating mixer.

To meet the percentage of approved grade of asphalt that can be easilyhandled and disperses well while still being able to be stored properlyunder ambient conditions, the asphalt packets can comprise a non-tackycoating which, when melted, forms a compatible part of the final mixturewhile not degrading the performance of the asphalt binder in thepavement. To meet the requirement of being stored at ambient temperatureand under pressure created by the weight of the asphalt packets withoutaggregate while still being free flowing when need to later be combinedwith aggregate, an asphalt packet which comprises asphalt that is fullyenclosed by a fully continuous, flexible non-tacky coating that iscompatible with the asphalt has been developed. The asphalt packet isfabricated such that the packet size and surface to volume ratio iswithin a range of meeting the fast melting properties required in theprocess such that when heated with the aggregate provides a high qualityhot mix at about 300° F. without exposing the asphalt to excessive heatfor extended time which causes oxidation and consequent degradation ofthe asphalt.

Asphalt packets which comprise a non-tacky continuous coating asdisclosed herein can comprise at least about 85% by weight ofhigh-quality virgin asphalt and can be stored in appropriate containersat ambient temperature for at least 1 year and retain its free-flowingproperties. The asphalt packets as disclosed herein can have a size andshape which, when heated to 300° F. from an ambient temperature in arotating mixer with an acceptable gradation of proper ratio of highquality aggregate will produce a quality usable hot mix at about 280° F.to about 300° F. The asphalt packets as disclosed herein will melt whenmixed with the correct ratio of aggregate in a rotating mixer atapproximately the same rate as the aggregate heats up thus coating theaggregate uniformly to produce high quality hot mix.

Thus, an asphalt forming process is disclosed herein that comprisesproviding an appropriate aggregate gradation and providing a pluralityof asphalt packets having non-tacky outer surfaces. Each of the asphaltpackets can comprise asphalt that comprises an inner volume. The asphaltcan be at least 85% by weight of high-quality virgin asphalt. Thepolymer film outer coating is non-tacky at ambient temperatures thatpermits stacking of a plurality of asphalt packets under weight withoutcausing the packets to agglomerate. The asphalt packets can have a sizeand shape to create a surface-to-volume ratio that permits the polymerfilm outer coating and the asphalt to fully melt into a liquid asphaltcomposite when heated to between about 260° F. and about 340° F. beforethe asphalt begins to degrade.

When the polymer film outer coating and the asphalt are melted together,an asphalt composite is formed. The polymer from the film coating andthe asphalt can comprise different amounts of the asphalt composite. Forexample, for an asphalt packet of generally rectangular shape of ⅛inch×½ inch×¾ inch and a polymer film outer coating having a thicknessof 4 mils, the asphalt comprises about 91% of the asphalt composite whenmelted and the polymer film coating comprises about 9% of the asphaltcomposite. In another embodiment, an asphalt packet of generallyrectangular shape of ¼ inch×½ inch×¾ inch and a polymer film outercoating having a thickness of 4 mils can be provided where the asphaltcomprises about 94% of the asphalt composite when melted and the polymerfilm coating comprises about 6% of the asphalt composite Each of theasphalt packets can also comprise a polymer film outer coating thatencapsulates the volume of the asphalt. Other examples of asphaltcomposite composition are provided below in Table 6 showing differentsized asphalt packets with polymer film outer coatings with differentthickness.

TABLE 6 Percentage of Composition of Asphalt Composite Upon Melting ofAsphalt Packet Percentage of Composition of Asphalt Composite UponMelting of Asphalt Packet Volumetric Polymer Asphalt Dimensions* PolymerCoating Polymer Coating Coating Packet in Inches Thickness ThicknessThickness Shape (H × W × L) (1 mils) (2 mils) (4 mils) Rectangular 1/8 ×1/2 × 3/4 About 2.25% About 4.5% About 9% Packet polymer polymer polymerAbout 97.75% About 95.5% About 91% asphalt asphalt asphalt Regtangular1/4 × 1/2 × 3/4 About 1.5% About 3% About 6% Packet polymer polymerpolymer About 98.5% About 97% About 94% asphalt asphalt asphalt

The process can also comprise providing a rotatable asphalt mixer and aheat source for heating contents placed in the rotatable asphalt mixer.The aggregate gradation and the plurality of asphalt packets can beinserted into the rotatable asphalt mixer and heated to temperatures ofbetween about 260° F. and about 340° F. to permit the asphalt packets tofully melt and coat the aggregate uniformly as the aggregate reaches amaximum mix temperature, and prior to degradation of the asphaltcomposite due to prolonged exposure to excessive temperature. In someembodiments, the asphalt mix can comprise between about 5% to about 10%of asphalt packets by weight and between about 90% to about 95%aggregate. For example, in one embodiment, the asphalt packets comprise6% and the aggregate comprises about 94% of the asphalt mix. In someembodiments, the aggregate gradation can be inserted into the rotationalmixer first and heated before inserting the asphalt packets into therotatable asphalt mixer and then heating both the aggregate and theplurality of asphalt packets. In some embodiments, both the aggregategradation and the plurality of asphalt packets can be inserted into therotatable mixer before beginning to heat the aggregate and the pluralityof asphalt packets.

The present disclosure also provides processes of making asphaltpackets. In some embodiments, the process of making asphalt packets cancomprise providing liquid asphalt and providing liquefied polymermaterial that can be used to create a polymer film outer coating. Theasphalt can comprise at least 85% of high-quality virgin asphalt. Thepolymer material can comprise one or more thermoplastic polymers thatcan be melted in a temperature range of between about 200° F. and about340° F. In some embodiments, the one or more thermoplastic polymers thatcan be used as the outer coating layer can comprise at least one ofethylene-vinyl acetate (EVA), styrenic block copolymers (SBC),styrene-butadiene-styrene (SBS) block copolymers andstyrene-ethylene-butylene-styrene (SEBS) polymers, such as those soldunder the tradename of KRATON™. Further, some combination of polymericblends of these polymers listed above can used.

As shown in FIG. 8, a cross-section of an extruder 80 that can coextrudeasphalt 12A and the polymer 14A into an extrudate 90 with the asphalt12A forming a core 92 of the extrudate 90 and the polymer materialforming an outer perimeter 94 of the extrudate 90 such that the polymerforms an outer surface of the extrudate 90. The extruder 80 can have afirst extruder 82 that houses and maintains the liquified asphalt 12Aand extrudes the asphalt 12 to form the core 92 while a second extruder84 that houses and maintains the liquified polymer 14A can extrude apolymer film outer coating 14 around the core 92 of asphalt 12 such thatthe polymer film outer coating 14 forms the outer perimeter 94 of thecoextrusion surrounding the core 92. The extrudate 90 can then be cooledand cut into asphalt packets 10 having a surface area to volume ratio of10 or greater. In some embodiments as shown in FIG. 8, for example, theextruder 80 can include driven and synchronized sealing rollers 86, 88that pinch or push the polymer film outer coating 14 together to formthe extrudate 90 into asphalt packets 10 by forming ends of the packets10. These sealing rollers 86, 88 can cut the asphalt packets 10 alongthe ends to form separate individualized packets 10 and cooled prior topackaging. Alternatively, in some embodiments, the sealing rollers 86,88 can perforate the ends so that the asphalt packets 10 can be easilyseparate as needed by the user of the asphalt packets 10.

In other embodiments of a process of making asphalt as shown in FIGS.9A-9C, sheets of polymer or rolls of polymer sheeting can be used. Insuch embodiments, the process of making asphalt packets 110 can compriseproviding a top sheet 114A, 114C of polymer and a bottom sheet 1148,114D of polymer.

Referring to FIGS. 9A and 9B, another coextrusion process is provided. Acoextruder 100 can be provided that can extrude a middle sheet ofliquified asphalt 112 and extrude a sheet 114A of thermoplastic polymeron top of the sheet of liquified asphalt 112 and extrude a sheet 1148 ofthermoplastic polymer beneath the middle sheet of liquified asphalt 112.In particular, the extruder 100 can comprise a top polymer extruder 102that can house polymer that can be extruded therefrom to form the topsheet 114A and a bottom extruder 104 that can house polymer that can beextruded therefrom to form the bottom sheet 1148. The extruder 100 cancomprise a middle extruder 106 that extrudes the liquefied asphalt 112between the top and bottom polymer sheets 114A, 114B. The middle sheetof asphalt 112 can have a thickness of about ⅛ of an inch and about ¼ ofan inch while the top and bottom polymer sheets 114A. 1148 can have athickness of between about 0.001 inches and about 0.01 inches (betweenabout 1 mil and about 10 mils). The top and bottom polymer sheets 114A,1148 and asphalt 112 together can be sealed into asphalt packets 110comprising an asphalt inner volume and a polymer film coating outersurface such that the asphalt packets 110 have a surface area to volumeratio of 10 or greater. For example, the extruder 100 can include drivenand synchronized sealing rollers 108, 109 that press the top and bottompolymer sheets 114A, 1148 at specific locations to form side seals 122and end seals 118 around the individual asphalt packets 110. Therotating sealing rollers 108, 109 press and seal the layers of middlesheet of asphalt 112 and top and bottom polymer sheets 114A, 114B intothe asphalt packets 110 while the layers are still hot. As the layersand the asphalt packets 110 formed by the layers cool down, the layersof sheets can be cut along the end and side seal joints to form separateand individual packets 110.

FIG. 9C shows a slight alternative embodiment, instead of extruding thetop and bottom sheets, a roll 130A of polymer sheeting to form the topsheet 114C of polymer and a roll 1308 of polymer sheeting to form thebottom sheet 114D of polymer and can be provided. The polymer sheetingfor the top and bottom polymer sheets 114C, 114D can be pulled from therolls 130A, 1308 as the asphalt is insert via extrusion onto the bottompolymer sheet 114D between the top and bottom polymer sheets 114C, 114D.For example, an extruder 132 can extrude the liquefied asphalt 112 ontothe bottom sheet 114D between the top and bottom polymer sheets 114C,114D. The middle sheet of asphalt 112 can have a thickness of about ⅛ ofan inch and about ¼ of an inch while the top and bottom polymer sheets114C, 114D can have a thickness of between about 0.001 inches and about0.01 inches (between about 1 mil and about 10 mils). Guide rollers 134,136 can be provided to ensure that the top and bottom polymer sheets114C, 114D abut the extruded sheet of asphalt 112. Asphalt packets canbe formed in a similar manner as the process shown in FIGS. 9A and 9B.For example, driven and synchronized sealing rollers can be providedthat press the top and bottom polymer sheets 114C, 1140 at specificlocations to form side seals and end seals around the individual asphaltpackets. The driven and synchronized sealing rollers can be heated toheat up the top and bottom polymer sheets 114C, 114D to seal themtogether. Once cooled, the asphalt packets can be cut into separateindividualized asphalt packets that can be stored in a container and canbe free-flowing from the container even after storage for extendedperiods of time.

To cut and seal the asphalt packets, in other embodiments, the top andbottom polymer sheets and asphalt together can be stamped into asphaltpackets comprising an asphalt inner volume and a polymer film coatingouter surface having a surface area to volume ratio of 10 or greater.For example, the top and bottom polymer sheets and asphalt together canbe stamped using one or more dyes that can form the shape of the asphaltpackets and seal the polymers from the top and bottom sheets together.

The solidified asphalt can be heated to liquefy the asphalt andproviding the liquefied asphalt to an extruder to extrude the liquefiedasphalt. In some embodiments, the solidified asphalt can be heatedbefore being fed to the extruder. In some embodiments, the solidifiedasphalt can be heated in the extruder during the extrusion process.

These and other modifications and variations to the present subjectmatter may be practiced by those of ordinary skill in the art, withoutdeparting from the spirit and scope of the present subject matter, whichis more particularly set forth herein above. In addition, it should beunderstood the aspects of the various embodiments may be interchangedboth in whole or in part. Furthermore, those of ordinary skill in theart will appreciate that the foregoing description is by way of exampleonly, and is not intended to limit the present subject matter.

What is claimed is:
 1. An asphalt forming process, the asphalt formingprocess comprising: providing an appropriate aggregate gradation;providing a plurality of asphalt packets having non-tacky outersurfaces, each of the asphalt packets comprising: asphalt that comprisesan inner volume; a polymer film outer coating that encapsulates thevolume of the asphalt, the polymer film outer coating being non-tacky atambient temperatures that permits stacking of a plurality of asphaltpackets under weight without causing the packets to agglomerate; thepolymer film outer coating and the volume of asphalt having a size andshape to create a surface-to-volume ratio that permits the melting ofthe polymer film outer coating and the asphalt into a liquid form whenheated to between about 260° F. and about 340° F. before the asphaltbegins to degrade; providing a rotatable asphalt mixer and a heat sourcefor heating contents placed in the rotatable asphalt mixer; insertingthe aggregate gradation into the rotatable asphalt mixer; inserting theplurality of asphalt packets into the rotatable asphalt mixer; heatingthe aggregate gradation and the plurality of asphalt packets totemperatures of between about 260° F. and about 340° F. to permit theasphalt packets to melt and coat the aggregate uniformly as theaggregate reaches a maximum mix temperature, and prior to degradation ofthe asphalt of the asphalt packets.
 2. The asphalt forming processaccording to claim 1, wherein the heating the aggregate gradation andthe plurality of asphalt packets comprises heating the aggregate firstthen performing the steps of inserting the asphalt packets into therotatable asphalt mixer and heating the aggregate and the plurality ofasphalt packets.
 3. The asphalt forming process according to claim 1,wherein both the aggregate gradation and the plurality of asphaltpackets are added to the rotatable mixer before beginning to heat theaggregate and the plurality of asphalt packets.
 4. The asphalt formingprocess according to claim 1, wherein the surface-to-volume ratio ofeach of the asphalt packet is at least about
 10. 5. The asphalt formingprocess according to claim 1, wherein the surface-to-volume ratio ofeach of the asphalt packet is between about 15 and about
 20. 6. Theasphalt forming process according to claim 1, wherein thesurface-to-volume ratio of each of the asphalt packet is greater thanabout
 17. 7. The asphalt forming process according to claim 1, whereinthe surface-to-volume ratio of each of the asphalt packet is greaterthan about
 20. 8. A process of making asphalt packets comprising:providing liquid asphalt; providing liquefied polymer; coextruding theasphalt and the polymer into an extrudate with the asphalt forming acore of the extrudate and the polymer forming an outer perimeter of theextrudate such that the polymer forms an outer surface of the extrudate;cutting the extrudate into asphalt packets having a surface area tovolume ratio of 10 or greater.
 9. The process of making asphalt packetsaccording to claim 8, wherein the surface-to-volume ratio of each of theasphalt packet is between about 15 and about
 20. 10. The process ofmaking asphalt packets according to claim 8, wherein thesurface-to-volume ratio of each of the asphalt packet is greater thanabout
 20. 11. The process of making asphalt packets according to claim8, wherein the polymer film outer coating comprises at least one ofethylene-vinyl acetate (EVA), styrenic block copolymers (SBC),styrene-butadiene-styrene (SBS) block copolymers,styrene-ethylene-butylene-styrene (SEBS) polymers, or combinationsthereof.
 12. A process of making asphalt packets comprising: providing abottom sheet of polymer and a top sheet of polymer; extruding liquefiedasphalt between the top and bottom polymer sheets; cutting and sealingthe top and bottom polymer sheets and asphalt together into asphaltpackets comprising an asphalt inner volume and a polymer film coatingouter surface having a surface area to volume ratio of 10 or greater.13. The process according to claim 12, wherein the step of providing abottom sheet of polymer and a top sheet of polymer comprises providingrolls of polymer sheeting from which the bottom sheet of polymer and thetop sheet of polymer can be cut.
 14. The process according to claim 12,further comprising heating solidified asphalt to liquefy the asphalt andproviding the liquefied asphalt to an extruder to extrude the liquefiedasphalt.
 15. The process according to claim 12, wherein the step ofcutting and sealing the top and bottom polymer sheets and asphaltcomprising stamping the top and bottom polymer sheets and asphalttogether into asphalt packets comprising an asphalt inner volume and apolymer film coating outer surface having a surface area to volume ratioof 10 or greater.
 16. The process according to claim 12, wherein theasphalt packets have a width of about 0.5 inches, a thickness of about0.2 inches, and a length of about 0.75 inches.
 17. The process accordingto claim 12, wherein the asphalt packets have a width of about 0.5inches, a thickness of about 0.15 inches, and a length of about 0.75inches.
 18. The process according to claim 12, wherein the asphaltpackets have a width of between about 0.3 and about 0.5 inches, athickness of about 0.1 and about 0.2 inches, and a length of about 0.50to about 1.5 inches.
 19. A non-tacky asphalt packet comprising: a volumeof asphalt; a continuous polymer film outer coating encapsulating thevolume of the asphalt, the polymer film outer coating being non-tackyand flexible at ambient temperatures; the polymer film outer coatingbeing compatible with the asphalt such that when the asphalt packet ismelted, the polymer film outer coating of the asphalt packet mixes withthe asphalt to form an asphalt composite; and the asphalt packetcomprising the polymer film outer coating and the volume of asphalthaving a surface-to-volume ratio that permits the melting of the polymerfilm outer coating and the asphalt when heated above a melting point ofthe asphalt such that the polymer film outer coating and asphalt liquefywithout degradation of the asphalt composite during a liquefactionprocess.
 20. The non-tacky asphalt packet according to claim 19, whereinthe polymer film outer coating comprises at least one of ethylene-vinylacetate (EVA), styrenic block copolymers (SBC),styrene-butadiene-styrene (SBS) block copolymers,styrene-ethylene-butylene-styrene (SEBS) polymers, or combinationsthereof.